Some Truths about Fracking, Part 1
Definitions: Fracking is hydraulic fracturing, a process where water (or similar liquid) is pumped down a well under high pressure. It is a proven technology in use for over 60 years. The pressure splits the rock like an axe splits a log, and creates fractures (cracks) in the rock containing the oil or gas.
The fractures grow in length and height, and act as conduits to allow the oil or gas faster access to the well. This means a higher production rate. The fractures are a bit like those you see in the sidewalk or roadway. They’re long but not very wide. Typical fracture widths are less than half an inch, and usually much smaller.
The revolution that is called shale gas or shale oil has been successful because many frac treatments are pumped one at a time along the length of a horizontal well.
This new technology has opened up enough conduits in the shale to get the gas out fast enough to make a profitable well. The revolution took off in the early 2000’s in the Barnett shale close to Fort Worth, Texas. Some wells have even been drilled under the DFW airport.
The benefits: The success in the Barnett has been transferred to several other shale basins, and this has caused the US supplies of oil and gas to turn upward after many years of decline. It has also forced the price of natural gas down.
The USA is becoming less dependent on foreign oil, and saving some of the massive dollar amounts it sends to other countries to buy the oil. In a few years the US may be exporting natural gas in liquefied form (called LNG) and actually making money. Although, building a new LNG train/terminal costs a few billion dollars (yes that’s billion) as Australia has recently found out.
The booming shale plays in the US are large job resources. The Bakken shale in North Dakota, and the Eagle Ford shale in south Texas are two examples. If you are out of work and go there, you will be able to find a job. A huge number of jobs has been provided by the shale oil and gas industries since the revolution started.
Burning natural gas in electrical generators is cheaper than burning coal, and generators are slowly changing over. Natural gas burns cleaner than coal or oil, and generates only about half of the CO2 that goes into the atmosphere.
Thus it is viewed by many as a half-way house for limiting greenhouse gases and their negative effects. Until the country gears more to sustainable methods such as wind turbines and solar collectors. Cars can also be run on natural gas, and many do in other countries such as Australia and India. However the US has been slow to move forward in this area.
Perceived problems: I shall address these separately.
Fracking contaminates surface water or water in aquifers. This is highly unlikely since most shale plays are deeper than 5,000 ft, and aquifers are normally shallower than 2000 ft. It is known that the fractures, although long and thin, do not usually grow upward more than a few hundred feet. This has been established by microseismic data. The fractures don’t get anywhere near the 2000 ft level of the deepest aquifers.
However, gas has occasionally been found in aquifers or at the surface, and this is generally due to poor well construction. After a well is drilled, steel casing is installed from the surface to the bottom of the well. Cement is then poured in outside the casing to fill the gaps between the casing and the rock formations.
If the casing of a well is not properly cemented against the rock all the way to the surface, the gas can seep upward. A situation like this caused the blowout of the Macondo oil well in the Gulf of Mexico a couple of years ago, which led to the release of large volumes of oil into the ocean. Oil companies need to be held accountable for contamination as a result of poorly cemented casing.
A tiny amount of seismic energy is released during a frac job. Hundreds of microseismic energy bursts may be recorded, but each is only equivalent to a gallon of milk falling off a kitchen counter. No damage has been reported in over a million frac jobs.
Shale fracking often uses ‘water fracs’ which means water containing a small amount of chemicals, The concentration is less than the chemicals in a swimming pool. Plus, sand grains called proppant to hold the fractures open after the high pressure diffuses away. In fact the concentration of water plus proppant is 99.5% of the total fluid injected.
The chemicals are to make the water slick (surfactant or “soap”), to prevent the shale in the rock from swelling. Also, to guard against bacterial growth underground (biocide) and things like that. Many of these additives are used in household products or foods that we eat. Although some shale fracs are pumped with more thickeners (gels) in the water. Therefore a higher percentage of chemicals, the chemicals stay deep in the ground because the fractures stay deep in the ground.
Even though huge volumes of water are used when fracking a long horizontal well. Lengths typically less than 5000 ft, but some are up to 10,000 ft long. The liquid cannot travel far from the fractures because shale rock is incredibly tight. the fractures stay at great depths as explained above. Approximately 30-50% of the injected water is recovered.
The huge volumes used in fracking can be a drain on a local water supply if city water is used. However, progress is being made toward using saltier water, such as water produced from other wells, or even sea water.
The intensive development of a shale play with many wells may lead to air pollution (as well as noise pollution) due to exhaust from engines that pump the frac fluid down the well. Also, due to escape of gas from the well structure (although this leakage is normally minor). Some oil wells still deliberately flare gas, but this is monitored by the Environmental Protection Agency (EPA).
Last is disposal of water produced by shale wells. When after fracking a well is turned on to production, some of the water produced is frac water and some is water that was originally in the shale. Apart from surface disposal, which is regulated and monitored by state environmental departments, there is underground disposal down specially designed wells.
If there are a lot of disposal wells receiving liquid at the same time, this may lead to a buildup of pressure over an area large enough to induce minor earthquakes. By minor is meant less than about 4 on the Richter scale which means the quakes may be felt at the surface but cause no damage. This appears to be the case in Ohio in 2011. Note that a 6 earthquake, which is 100 times more powerful, can cause serious damage.
Oil companies are actively trying to invent fracking schemes that use much less, or no water, and therefore lead to less produced water which has to be disposed of. In addition, guidelines have been proposed for reducing the likelihood of earthquakes. One such is to measure any seismic activity near the disposal wells. Then, to limit the injection of water into disposal wells if/when earthquakes are first observed. Finally, no earthquake induced by fluid disposal has caused significant injury or damage even though 140,000 disposal wells have operated safely in the US for decades.
P.S. I just heard (3 April) from a reliable source that Oklahoma recently registered a disposal-induced earthquake of magnitude over 5, and it DID cause some property damage. This supports deployment of the guidelines mentioned above, and it does seem rather urgent to do this. There would be a huge outcry if even one person were killed in such an earthquake.
Safer wells will ease legitimate concerns that have been raised, and allow the US to enjoy the many benefits. When using the new technology, oil and gas companies need to keep their hands clean. Safety issues that are being addressed include:
• Construct wells with cement that tightly bonds the casing to the rock all the way along a well to the surface. Also, with tight joints to prevent leakage in the above-ground “Christmas tree”.
• Work with the EPA to define new standards to control all emissions from oil and gas well activities.
• Learn how to re-use produced water for the next frac job and thus conserve water. And figure out ways to reduce or replace frac water with other fluids. Like, liquefied natural gas which would eventually come out of the well with the original gas in the shale formation.
• Impose guidelines to monitor potential earthquakes near disposal wells, and limit injection volumes and rates accordingly.
Western Europe imports about a third of its natural gas from Russia (and the pipeline comes through Ukraine!) Germany imports 40%. Thus Europe doesn’t seem to have a winning hand for installing economic sanctions against Russia for the Crimea takeover.
At the same time some countries like France have prohibited the use of fracking, which is part of the new technology needed to develop shale gas. Since shale gas might serve to replace Russia’s gas, maybe Europe should rethink their fracking politics. However, other countries like Poland are steaming full ahead to develop their large deposits of shale gas.
The Gray Nomad.
Probing the practice of Christian believers……
The earth is the LORD’s, and the fulness thereof. The world, and they that dwell therein. For he hath founded it upon the seas, and established it upon the floods. Who shall ascend into the hill of the LORD? Or who shall stand in his holy place? He that hath clean hands, and a pure heart. Who hath not lifted up his soul unto vanity, nor sworn deceitfully (Psalm 24).
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Thanks for sharing this, Ian. I wonder a lot about Fracking, but more positive to me than negative and this moves me toward “its ok”. I am excited that our own companies are having such success in moving us towards energy independence. I have a lot of interest in it because I trade oil, gas, and pipeline stocks. It changes all the time but today I have Rosetta Resources, Resolute Energy, and Kinder Morgan and, of course, I want them moving forward to make money so I can, LOL. Keep the great blog humming, my friend.
Dale, shale gas and shale oil are definitely moving the US toward energy independence, which is a good thing. If oil and gas companies lower the risk of accidents and pollution, that is a good thing too.
Yes, there has been too much messiness in the process of extracting fossil fuels, leaving irreparable damage. As far as other energy sources, I have a windmill and solar panel on my Amazon wish list, LOL. Am waiting for the more efficient products to emerge though.
Hi Uncle Ian, this was a very informative and interesting case for shale gas. Well put and easy to understand for this lay person. I now know facts not just hear say. Very enlightening. You are right that companies need to be held accountable for their actions. Unfortunately in this day and age a quick profit is more important than the health of our planet, and big business don’t experience the repercussions they should in courts of law. All of these things combined make me nervous about this process because all it takes is a few unscrupulous companies (e.g. the Gulf of Mexico Oil spill) to do so much irreparable damage. Do you think there is a renewable energy solution that could be used to replace our addiction to fossil fuels? Should we be investing these billions on sustainable energy industry? I am really interested to hear your response. I value your opinion.
Hi Robyn, to answer your question, in the US only a few % of energy needs are from wind and solar sustainables (but countries like Germany have a much higher %). This is why natural gas, which burns twice as clean as oil and coal, makes a good halfway house for electricity generation, transportation, etc. The current US government allocated a lot of “stimulus” funds five years ago to improve wind and solar technologies. This is paying off. A couple of examples. There are huge solar arrays in California which focus their sunlight on a central converter, which should be more efficient. An MIT professor announced recently a new type of battery that can store MUCH more solar or wind energy than all previous batteries, and this may be a game-changer.
I am really pleased that the US is researching and investing in clean energy. It does sound like a good “meanwhile” solution. Thanks for informing me.
A good dispassionate summary of a subject which can become quite emotive. I didn’t pick up in your article the difference in water management between coalbed methane (where I understand water is present in the coal strata and comes up continuously with the gas) and shale gas which I understand is normally from rock and is dry – the only water involved is that which is used to do the fracking. Do you have a comment on this?
Neil, water produced from wells (either shale gas or coalbed methane) is a mix of frac water and formation water. The mix and the total volume varies with well location, producing formation, and age of the well. A couple of generalizations: First, coalbed methane wells have a higher water saturation at the start, and produce relatively more water-to-gas ratio than shale wells. Second, in shale gas wells, only 30-50% of the frac water is recovered.
This is one of the best articles I have read on this subject. I am involved in the legal transactions of the petroleum industry and Dr. Palmer is spot on. There is no tolerance by other oil companies for those that take short cuts. The damage to the environment is unacceptable. The reputation of the industry rides on a thin line anyway in the current culture and we all know it. Therefore it would be foolish, and is foolish, to not strive for excellence. One other note, one of the main ingredients for the frack fluid is guar, as in guar gum, it acts like corn starch to thicken the fluid and keep the proppant in suspension as it is pumped into the fractured rock. It is all natural. There are synthetic versions but guar still remains one of the top choices. Just like a restaurant needs good reports from the health department to stay in business so do the oil and gas companies need good processes for them to stay in business – and they are there to stay in business.
Dear Jeff, thanks for your comment reflecting the perspective of the oil/gas companies. You have added clarity concerning this perspective, which has often been under-rated in my opinion.
Thanks for posting this very informative entry on fracking. It was nice to meet you on the WOW we hike!
Thanks for this comment Rebekah. I enjoyed our sharings on the hike about physics and careers.
Hi Ian. An interesting NAS (National Academy of Sciences) study was just published that seems to back up some of your hypotheses. It shows that at least in the 8 well clusters they researched in the Bakken and Marcellus that the water contamination of the water table wasn’t due to fracking but was due to cementing and casing issues. Hopefully more science like this is published in future years so we change make policy changes where they really need to be made to keep things progressing sustainably. Enjoy. http://www.pnas.org/content/111/39/14076.full
Thanks for sharing Kelly……much appreciated. Enjoyed our interactions in Durango.